E2UNDO(8) System Manager's Manual E2UNDO(8)

# [NAME](#NAME)

e2undo - Replay an undo log for an ext2/ext3/ext4 file system

# [SYNOPSIS](#SYNOPSIS)

**e2undo** \[ **-f** ] \[ **-h** ] \[ **-n** ] \[ **-o** *offset* ] \[ **-v** ] \[ **-z** *undo\_file* ] *undo\_log device*

# [DESCRIPTION](#DESCRIPTION)

**e2undo** will replay the undo log *undo\_log* for an ext2/ext3/ext4 file system found on *device*. This can be used to undo a failed operation by an e2fsprogs program.

# [OPTIONS](#OPTIONS)

[**-f**](#f)

Normally, **e2undo** will check the file system superblock to make sure the undo log matches with the file system on the device. If they do not match, **e2undo** will refuse to apply the undo log as a safety mechanism. The **-f** option disables this safety mechanism.

[**-h**](#h)

Display a usage message.

[**-n**](#n)

Dry-run; do not actually write blocks back to the file system.

[**-o offset**](#o)

Specify the file system's *offset* (in bytes) from the beginning of the device or file.

[**-v**](#v)

Report which block we're currently replaying.

[**-z undo\_file**](#z)

Before overwriting a file system block, write the old contents of the block to an undo file. This undo file can be used with [e2undo(8)](/man/os/e2fsprogs/e2undo.8) to restore the old contents of the file system should something go wrong. If the empty string is passed as the undo\_file argument, the undo file will be written to a file named e2undo-*device*.e2undo in the directory specified via the *E2FSPROGS\_UNDO\_DIR* environment variable.

WARNING: The undo file cannot be used to recover from a power or system crash.

# [AUTHOR](#AUTHOR)

**e2undo** was written by Aneesh Kumar K.V. (aneesh.kumar@linux.vnet.ibm.com)

# [AVAILABILITY](#AVAILABILITY)

**e2undo** is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.

# [SEE ALSO](#SEE_ALSO)

[**mke2fs**(8)](/man/os/e2fsprogs/mke2fs.8), [**tune2fs**(8)](/man/os/e2fsprogs/tune2fs.8)

March 2025 E2fsprogs version 1.47.4

---

Document: e2undo(8) from e2fsprogs 1.47.4-r5 (Chainguard OS)
Source: https://github.com/tytso/e2fsprogs